1. Field of the Invention
The present invention relates to an air-conditioner system including a plurality of air-conditioners each of which is a heat exchanger for either heating or cooling air in a room.
2. Description of Related Art
A prior-art air-conditioner system including a plurality of air-conditioners is proposed in, for example, Japanese Patent Unexamined Publication No. 49-127254, wherein a plurality of four-ports-connection-valves (i.e., valves having four ports) are respectively connected to the air-conditioners and a plurality of outdoor-radiators are respectively connected to the air-conditioners, so that each of the air-conditioners can selectively either heat or cool the air in the room. In the prior-art air-conditioner system, when at least one of the air-conditioners is stopped, the high-pressure refrigerant is stationarily held between an output of a compressor and the stopped air-conditioner, and the high-pressure refrigerant liquefies in accordance with a decrease in temperature thereof. Therefore, there is a possibility of a large amount of the liquefied refrigerant being held stationary between the output of the compressor and the stopped air-conditioner and the amount of the refrigerant capable of flowing in the air-conditioner system becoming undesirably decreased.